About 22 minutes later, Perkins died -- a death the police say was entirely predictable, because Perkins was on
the department’s strategic subjects list, a list of 1,400 individuals at high risk
in the city’s epidemic of violence.

Eighty-five percent of Chicago’s victims or victimizers are on that list -- a compendium of ages, records, associates and even wounds that helps track trouble -- data culled
from the 600 gang factions and 100,000 documented gang members in this
city.

“We can see the people associated wtih that gang faction,” says Jonathan Lewin, the deputy chief of technology. “At the end of the day, the goal of this entire program is to save lives.”